Alarm system

ABSTRACT

An alarm system is provided in which an alarm condition causes a cellular transceiver automatically to transmit a telephone call to an alarm monitoring station by over-the-air transmission of a signal to a cellular site. A computer at the cellular site will cause communication between the cellular transceiver and an alarm company monitoring station. The alarm system includes a digital communicator with an alarm signal line connected to the digital communicator. The digital communicator is coupled to a cellular transceiver having a programmed keyboard, an audio input and an audio output. The digital communicator has an audio output and an interrogation input. The digital communicator&#39;s audio output is coupled to the cellular transceiver&#39;s audio input. The cellular transceiver&#39;s audio output is coupled to the digital communicator&#39;s interrogation input. The digital communicator includes a transmit enable output and a receive enable output. The cellular transceiver includes a transmit enable data line and a receive enable data line. The transmit enable output is coupled to the transmit enable data line and the receive enable output is coupled to the receive enable data line. An alarm signal received by the digital communicator causes the transmit enable output to transmit a signal to the transmit enable data line thereby enabling the cellular transceiver to transmit the telephone call via over-the-air transmission to the cellular site from where it is relayed to the alarm monitoring station.

BACKGROUND OF THE INVENTION

The present invention concerns a novel alarm system and, moreparticularly, an alarm system which avoids the problems concomitant withalarm systems that are wired to an alarm monitoring station.

It is typical for alarm systems, such as burglar alarm systems, to beconnected via telephone lines to an alarm monitoring station. Forexample, the premises typically have a protective circuit which maycomprise a number of intrusion detectors, a voltage source, a sensingrelay and wiring connecting these components in series. The alarm systemgenerally includes an alarm control panel where the sensing relay may belocated, a key operated switch, and a latching relay. When an alarmcondition occurs, the latching relay is caused to activate an audibleand/or visible warning device and/or a signal that is transmitted viatelephone lines to a police station or central office. In someinstances, a dedicated telephone line from the premises to the policestation is used. In other instances, a shared telephone line is used anda particular signal is issued on the telephone line corresponding to thealarm condition that has occurred.

An essential link between the protected premises and the police stationor central office is the telephone line. However, the telephone wire maybe cut and the voltage may be simultated, which will prevent the policestation or central office from receiving the alarm communication.

It is, therefore, an object of the present invention to provide an alarmsystem in which there are no telephone lines connecting the protectedpremises to a police station or central office.

Another object of the present invention is to provide an alarm systemthat enables a telephone call to be made to an alarm monitoring stationwhen an alarm condition occurs, without the problems concomitant with ahard wired system.

A further object of the present invention is to provide an alarm systemthat is reliable in operation, and uses wireless, over-the-airtransmission without the restricted number of radio channel frequenciesavailable with conventional mobile telephone systems. One of the seriousproblems with conventional mobile telephone systems is the restrictednumber of radio channel frequencies that are available, which may resultin a substantial time period before an open line is available. Therestricted number of available radio channel frequencies that areavailable with conventional mobile telephone systems seriously hampersthe use of such systems in connection with premises that are protectedby an alarm system.

Other objects and advantages of the present invention will becomeapparent as the description proceeds.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with the present invention, an alarm system is providedwhich utilizes cellular telephone communication. A cellular systemincludes a continuous pattern of hexagon-shaped coverage areas (i.e.,cells). Within each cell is a centralized base station containingcontrol equipment for the channels assigned to that cell. All of thecells within a system communicate with each other and with a centralcontrol site, i.e., the telephone company.

The cellular system offers a great amount of capacity by usingrelatively low power transmitters and by segmenting each geographic areainto cells. When the cellular system approaches optimal loading, thecells effectively split, and each cell is divided into still smaller,lower power cells. This permits reuse of channels and extends thesystem's loading capacity.

In the illustrative embodiment, the alarm system includes a digitalcommunicator and means for connecting an alarm signal line to thedigital communicator. The cellular transceiver has a programmedkeyboard, an audio input and an output. The digital communicator has anaudio output and an interrogation input. The digital communicator audiooutput is coupled to the cellular transceiver audio input. The cellulartransceiver audio output is coupled to the digital communicatorinterrogation input. An antenna is connected to the cellulartransceiver. In this manner, the alarm signal received by the digitalcommunicator will operate the cellular transceiver to transmit anover-the-air signal to a cellular site. From the cellular site a signalcan be forwarded to an alarm monitoring station with the alarmmonitoring station being placed in communication with the cellulartransceiver via the cellular site.

In the illustrative embodiment, the digital communicator includes aplurality of alarm inputs. Each of the inputs represents a selectedlocation or a different alarm condition.

In the illustrative embodiment, the digital communicator includes atransmit enable output and a receive enable output. The keyboardincludes a transmit enable data line and a receive enable data line. Thedigital communicator receive enable output is connected to the keyboardreceive enable data line, and the digital communicator transmit enableoutput is connected to the keyboard transmit enable data line.

In the illustrative embodiment, the digital communicator and cellulartransceiver are operable in a manner whereby an alarm signal received bythe digital communicator will cause the transmit enable output totransmit a signal to the transmit enable data line. This will enable thecellular transceiver to transmit a call from a programmed telephonenumber via over-the-air transmission to a cellular site. The cellularsite can communicate with an alarm monitoring station which will causethe transmission of an over-the-air signal to the cellular transceiveraudio output. This will cause a signal to be transmitted to the digitalcommunicator interrogation input, with a code signal being transmittedfrom the digital communicator audio output to the cellular transceiveraudio input and then be transmitted over the air to the cellular site.

A more detailed explanation of the invention is provided in thefollowing description and claims, and is illustrated in the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an alarm system constructed in accordancewith the principles of the present invention;

FIG. 2 is a schematic circuit diagram of a portion of the digitalcommunicator of the alarm system of FIG. 1; and

FIG. 3 is a schematic circuit diagram of another portion of the digitalcommunicator of FIG. 1 and a portion of the keyboard of the cellulartransceiver of FIG. 1.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

Referring to FIG. 1, an alarm control panel 10 is shown therein. Alarmcontrol panel 10 is of a conventional type, and has a plurality of inputlines 12, 14, 16 and 18. Each of the input lines is connected to anintrusion detector as is well-known in the art. Alternatively, each ofthe input lines 12-18 may be connected to a different protectedlocation, with the various locations utilizing the same alarm controlpanel 10. In the illustrative embodiment, input line 12 is connected tozone 1, input line 14 is connected to zone 2, input line 16 is connectedto zone 3 and input line 18 is connected to zone 4.

An audible warning device 20, which in the illustrative embodiment is abell, is connected to alarm control panel 10 via line 22.

The alarm control panel 10 has output alarm signal lines 24, 26, 28 and30 which carry signals corresponding to the signals on lines 12, 14, 16and 18, respectively. Alarm signal lines 24-30 are connected to adigital communicator 32 with line 24 being connected to zone 1 input 34,line 26 being connected to zone 2 input 36, line 28 being connected tozone 3 input 38 and line 30 being connected to zone 4 input 40.

Digital communicator 32 is shown in more detail in FIGS. 2 and 3. In theillustrative embodiment, the digital communicator is preferably an AcronDD3 digital communicator to which certain modifications have been made.The Acron digital communicator with modifications is illustrated in FIG.2 and a digital interface which forms part of the digital communicatoris illustrated in FIG. 3. The zone inputs 34, 36, 38 and 40 areillustrated in FIG. 2 and are coupled to inputs of NAND gates 42, 44, 46and 48, respectively. These NAND gates act as buffers. Resistors 50, 52,54 and 56 are pull-down resistors which require a logic level high toinitialize the system. If the resistors were removed, a logic level lowwould initialize the system. The customer identification number and thestatus number are contained in an address PROM 58 which is connected tothe microprocessor strobe lines 60.

Referring back to FIG. 1, digital communicator 32 includes aninterrogation input 62, an audio output 64, a receive enable output 66,and a transmit enable output 68. Interrogation input 62 and audio output64 are also illustrated in FIG. 2. In the illustrative embodiment, theaudio output is a dual tone multiple frequency (DTMF) output.

The receive enable output 66 and the transmit enable output 68 form partof an interface circuit which is illustrated in FIG. 3. Referring toFIG. 3, the circuit includes one 4011 quad two-input NAND gate package70, a first 555 timer 72, a second 555 timer 74, a first output controltransistor 76, a second output control transistor 78, a first outputcontrol relay 80, and a second output control relay 82.

Referring to FIG. 2, when there is an alarm condition at zone inputs 34,36, 38 or 40, transistor 84 is energized, activating relay 86 andcausing arm 81 to transition from the logic level low to the logic levelhigh (12 volts DC). Arm 88 is connected to input S1 of FIG. 3. When alow to high logic input signal is received at input S1, contacts S2, S3of relay 80 will close momentarily to provide a short pulse. When a highto low logic input signal occurs at input S1, contacts S4, S5 of relay82 will close momentarily to provide a short pulse. Contacts S2, S3comprise the transmit enable output 68 of the digital communicator andcontacts S4, S5 comprise the receive enable output 70 of the digitalcommunicator.

Referring back to FIG. 1, it can be seen that digital communicator 32 iscoupled to a cellular transceiver 84. A ground line 86 is provided and a12 volt DC line 88 is also provided. Digital communicator audio output64 is connected by a transmit audio line 90 to a transmit audio input 92of the cellular transceiver. A receive audio output 94 of the cellulartransceiver is coupled via receive audio line 96 to interrogation input62.

The digital communicator 32 is also connected to a keyboard of thecellular transceiver. In the illustrative embodiment, the digitalcommunicator receive enable output 66 is connected via line 98 to thereceive enable data line of the keyboard. The digital communicatortransmit enable output 68 is connected via line 100 to the transmitenable data line of the keyboard.

In the illustrative embodiment, cellular transceiver 84 is a WesternUnion cellular transceiver, Model 1154A103A. The control head logicportion of this Western Union cellular transceiver is illustrated in twocircuit diagrams which are attached as an appendix to thisspecification, and may be referred to if necessary. As illustrated inFIGS. 2 and 3 of the drawings, and also in the circuit diagrams attachedin the appendix, the keyboard is shown with receive enable output line98a (FIG. 3) being connected to contact R6 and with receive enableoutput line 98b being connected to contact C3. Transmit enable outputline 100a is connected to contact R6 and transmit enable output line100b is connected to contact C1. In the circuit diagram in the appendix,the receive audio output of the cellular transceiver is designated as"RX VOICE" and the transmit audio input of the cellular transceiver isdesignated as "TX VOICE". Thus referring to FIG. 2, audio output 64 ofthe digital communicator is connected to the "TX VOICE" input of theWestern Union cellular transceiver. Likewise, the "RX VOICE" output ofthe Western Union cellular transceiver is connected to the digitalcommunicator interrogation input 62.

In the operation of the device, it may be assumed that an alarmcondition exists in zone 1. An alarm signal will be sent on line 12 toalarm control panel 10. This will provide a high input signal via line24 at zone 1 input 34 of digital communicator 32. Transistor 84 (FIG. 2)will conduct to energize relay 86 causing relay 80 (FIG. 3) to beenergized, thereby closing contacts 68 and providing a signal pulse onlines 100a, 100b to the transmit enable data input of the keyboard.

When the device was installed by the alarm company, the keyboard wasprogrammed with the telephone number of the alarm monitoring station.The signal on lines 100a, 100b will cause the keyboard transmit enableline to effectively dial the telephone number of the alarm monitoringstation. This telephone call will be transmitted via antenna 104, whichis connected to cellular transceiver 84, with an over-the-airtransmission to antenna 106 of a cellular site 108. The computer atcellular site 108 is hard wired through a central control site ortelephone company 110 which is hard wired to an alarm monitoring station112. In this manner, the telephone call is picked up at cellular site108 and transmitted to alarm monitoring station 112. The alarmmonitoring station answers the ring and then sends out a "handshake"tone which is transmitted by the cellular site 108 back to cellulartransceiver 84 in an over-the-air transmission. This "handshake" tone isreceived by the receive audio output 94 of cellular transceiver 84. Thistone, which is approximately a 2100 hertz signal, is transmitted vialine 96 to the interrogation input 62 of the digital communicator 32.This will command the digital communicator to send out the appropriateinformation.

While the digital communicator normally sends a DTMF signal to thetelephone line, in the instant application a 2200 hertz pulse signal istransmitted from audio output 64 via line 90 to the transmit audio input92 of the cellular transceiver. This pulse signal identifies thesubscriber (i.e., location) and the emergency code, at the rate of aboutten pulses per second, with each pulse representing a digit. Thecellular transceiver transmits, in an over-the-air transmission, thisidentification pulse signal to the cellular site 108. The identificationpulse signal is then transmitted from cellular site 108 to the alarmmonitoring station 112 and the alarm monitoring station computer is theninformed of the status, such as who the customer is, whether it is arobbery, a fire, a burglary, etc. Alarm monitoring station computer 112then sends another "handshake" or "request to send" signal that istransmitted from the cellular site 108 to the receiver audio output 94of cellular transceiver 84 in an over-the-air transmission. This"handshake" signal is fed via line 96 to the interrogation input 62 ofdigital communicator 32, effectively requesting a verification signal.Another 2200 hertz pulse identification signal is provided at audiooutput 64 and is transmitted via line 90 to the transmit audio input 92of cellular transceiver 84. It is then transmitted to the cellular site108 in an over-the-air transmission and is forwarded to alarm monitoringstation 112. The alarm monitoring station 112 computer will print theidentification information each time it is received such as "202 code1". If the same identification is received twice, it is considered to beverified and the alarm monitoring station 112 will send a "kiss-off"tone which is transmitted by the cellular site 108 in an over-the-airtransmission to the cellular transceiver 84. In addition, the alarmmonitoring station 112 will telephone the police or take whatever actionis appropriate.

It can be seen that a novel alarm system has been provided which isrelatively tamperproof compared to the alarm systems utilizing telephonelines that are hard wired from the protected premises to a policestation or a central office. Although an illustrative embodiment of theinvention has been shown and described, it is to be understood thatvarious modifications and substitutions may be made by those skilled inthe art without departing from the novel spirit and scope of the presentinvention.

What is claimed is:
 1. An alarm system for a protected premises at afixed location, which comprises:a digital communicator; means forconnecting an alarm signal line to said digital communicator; a cellulartransceiver, said cellular transceiver having programmable means, anaudio input and an audio output; said digital communicator having anaudio output and an interrogation input; means coupling said digitalcommunicator audio output to said cellular transceiver audio input;means coupling said cellular transceiver audio output to said digitalcommunicator interrogation input; an antenna connected to said cellulartransceiver, whereby an alarm signal received by said digitalcommunicator will operate said cellular transceiver to transmit anover-the-air signal to a cellular site, where it can be forwarded to analarm monitoring station with the alarm monitoring station being placedin two-way communication with the cellular transceiver via the cellularsite.
 2. An alarm system as described in claim 1, in which said digitalcommunicator includes a plurality of alarm inputs, with each of theinputs representing a selected location or emergency condition.
 3. Analarm system as described in claim 1, in which said digital communicatorincludes a transmit enable output and a receive enable output and saidprogrammable means comprises a keyboard having a transmit enable dataline and a receive enable data line, means connecting said digitalcommunicator receive enable output to said keyboard receive enable dataline and means connecting said digital communicator transmit enableoutput to said keyboard transmit enable data line.
 4. An alarm system asdescribed in claim 1, in which said digital communicator audio outputcomprises a dual tone multiple frequency (DTMF) output.
 5. An alarmsystem as described in claim 1, in which said digital communicatorincludes a transmit enable output and a receive enable output, saidcellular transceiver includes a transmit enable data line and a receiveenable data line, means coupling said transmit enable output to saidtransmit enable data line, and means coupling said receive enable outputto said receive enable data line; said digital communicator and cellulartransceiver being operable in a manner whereby an alarm signal receivedby said digital communicator will cause said transmit enable output totransmit a signal to said transmit enable data line enabling saidcellular transceiver to transmit a call from a programmed telephonenumber via over-the-air transmission to a cellular site, the cellularsite can communicate with an alarm monitoring station which will causethe transmission of an over-the-air signal to said cellular transceiveraudio output, thereby causing a signal to be transmitted to the digitalcommunicator interrogation input, with a code signal being transmittedfrom said digital communicator audio output to the cellular transceiveraudio input and then transmitted over the air to said cellular site andforwarded to the alarm monitoring company.
 6. An alarm system asdescribed in claim 1, in which said digital communicator includes aplurality of alarm inputs, with each of the inputs representing aselected location or emergency condition; said digital communicatoraudio output comprising a dual tone multiple frequency (DTMF) output;said digital communicator including a transmit enable output and areceive enable output; said programmable means comprising a keyboardhaving a transmit enable data line and a receive enable data line; meansconnecting said digital communicator receive enable output to saidkeyboard receive enable data line; and means connecting said digitalcommunicator transmit enable output to said keyboard transmit enabledata line.
 7. A system for providing a relatively tamperproof alarm of aprotected premises at a fixed location, which comprises the stepsof:providing a digital communicator having an audio input and aninterrogation input; coupling an alarm signal line to said digitalcommunicator; providing a cellular transceiver having a programmablemeans, an audio input and an audio output; coupling said digitalcommunicator audio output to said cellular transceiver audio input;coupling said cellular transceiver audio output to said digitalcommunicator interrogation input; when an alarm condition occurs,providing a signal from said digital communicator to said cellulartransceiver to automatically transmit an over-the-air signal to acellular site, where it can be forwarded to an alarm monitoring stationwith the alarm monitoring station being placed in two-way communicationwith the cellular transceiver via the cellular site.
 8. A system asdescribed in claim 7, in which said digital communicator includes atransmit enable output and a receive enable output and said programmablemeans comprises a keyboard having a transmit enable data line and areceive enable data line; and including the step of coupling saiddigital communicator receive enable output to said keyboard receiveenable data line and the step of connecting said digital communicatortransmit enable output to said keyboard transmit enable data line.
 9. Asystem as described in claim 8, wherein an alarm signal received by saiddigital communicator will cause said transmit enable output to transmita signal to said transmit enable data line enabling said cellulartransceiver to transmit a programmed telephone number via over-the-airtransmission to a cellular site, the cellular site can communicate withan alarm monitoring station which will cause the transmission of anover-the-air signal to said cellular transceiver audio output, therebycausing a signal to the transmitted to the digital communicatorinterrogation input, with a code signal being transmitted from saiddigital communicator audio output to the cellular transceiver audioinput and then transmitted over the air to said cellular site. .Iadd.10. An alarm system for a protected premises at a fixed location, whichcomprises:a digital communicator; means for connecting an alarm signalline to said digital communicator; a cellular transceiver, said cellulartransceiver having an audio input and an audio output; said digitalcommunicator having an audio output and an interrogation input; meanscoupling said digital communicator audio output to said cellulartransceiver audio input; means coupling said cellular transceiver audiooutput to said digital communicator interrogation input; an antennaconnected to said cellular transceiver, whereby an alarm signal receivedby said digital communicator will operate said cellular transceiver totransmit an over-the-air signal to a cellular site, where it can beforwarded to an alarm monitoring station with the alarm monitoringstation being placed in two-way communication with the cellulartransceiver via the cellular site. .Iaddend. .Iadd.
 11. A system forproviding a relatively tamperproof alarm of a protected premises at afixed location, which comprises the steps of:providing a digitalcommunicator having an audio input and an interrogation input; couplingan alarm signal line to said digital communicator; providing a cellulartransceiver having an audio input and an audio output; coupling saiddigital communicator audio output to said cellular transceiver audioinput; coupling said cellular transceiver audio output to said digitalcommunicator interrogation input; when an alarm condition occurs,providing a signal from said digital communicator to said cellulartransceiver to automatically transmit an over-the-air signal to acellular site, where it can be forwarded to an alarm monitoring stationbeing placed in two-way communication with the cellular transceiver viathe cellular site. .Iaddend.